Ring gauge



May 23, 1950 s. HOHWART ET AL 2,508,326 RING GAUGE Filed Jan. 31, 1946 lN V EN TOR-5' E- flab/m? 2 5277652 Fflcgari,

W fim Patented May 23, 1950 RING GAUGE George Hohwart and Ernest F.Hohwart, Detroit, Mich., assignors to N. A. Woodworth Company, Ferndale,Mich., a corporation of Michigan Application January 31, 1946, SerialNo. 644,604

11 Claims.

This invention relates broadly to new and useful improvements inadjustable ring gages and more particularly to an improved means forradially adjusting the gage body.

In conventional ring gages, the gage body is contractible so that thediameter ofthe gaging bore can be adjusted. Although the range ofadjustment is usually small, difficulty is sometimes encountered inmaking even a relatively small adjustment by a light weight,mechanically simple and manually operable means. One thing that makesthe gage difiicult to adjust is the gage body itself which is arelatively heavy, annular piece of metal that offers considerableresistance to contraction. The gage is handled manually and should be aslight as possible; however, since it is occasionally dropped orotherwise jolted severely in use, it also must be strong and rugged inconstruction. Thus, not only should the gage be easily adjusted andlight in weight, but the adjusting means must hold the body rigid and inproper adjustment during normal handling and abuse.

An important object in the present invention is to provide a ring gagehaving novel means for applying radially compressive forces against thegage body.

Another object of the invention is to provide a ring gage in which agreater proportion of the force imposed by the adjusting means istransmitted radially against the gage body.

Still another object of the invention is to provide a ring gage of theabove type that is light in weight.

Yet another object of the invention is to provide an adjustable ringgage that is simple in construction, yet sufficiently strong and ruggedto withstand normal handling and abuse.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the drawing forming a part of this specification and wherein likenumerals are employed to designate like parts throughout the same,

Fig. 1 is a side elevational view of an adjustable ring gage embodyingthe invention,

Fig. 2 is a diametric sectional view taken on the line 2-2 of Fig. 1,

Fig. 3 is a fragmentary view similar to Fig. 2 showing one means foractuating the adjusting elements which contract the gage body, and

Fig. 4 is an enlarged, fragmentary view similar to Fig. 2 but showing amodified means for adjusting the gage body.

Considered in certain of its broader aspects,

the ring gage embodying the instant invention is generally similar tothe gage disclosed in our copending application Serial No. 562,058,which was filed November 6, 1944, and matured into patent No. 2,413,566on the 31st day of December, 1946. All of the advantages alleged for theprior device are inherent in the present construction, and, in addition,the latter is uniquely formed to substantially increase the pressurethat is exerted against the gage body by a given application of force tothe adjusting members.

More specifically, the present construction includes a split metal wireor ring which is carried by the body and is simultaneously engaged byreentrant bearing surfaces on the adjusting elements. This ring limitsinward movement of the adjusting elements and thus automatically centersthe gage body longitudinally in the elements. Furthermore, tightening ofthe adjusting elements applies radial pressure on the bodysimultaneously through the thread surfaces and ring. Thus, the presentconstruction exerts substantially the same amount of pressure throughthe thread surfaces as is exerted by the previous construction and, inaddition, applies radial thrust through the split metal ring, Theincrement of force exerted through the metal ring is substantial and isestimated to be roughly equal to' the pressure exerted by the totalthread surfaces.

For a more detailed description of the invention reference is had to theaccompanying drawings, wherein the numeral [0 designates the gage bodyand the numerals I2 and I4 designate the adjusting elements or rings.

The gage body II] is provided with a gaging bore l6 which is adapted toreceive and snugly fit a workpiece to be tested. In so far as thepresent invention is concerned it is immaterial whether the bore It beplain or threaded; however, for the purpose of illustration, the bore isshown with internal screw threads [8.

In order to make the body [0 radially contractible it is provided withthe usual locking slot 20 and adjusting slots 22. The former extendsentirely through the body, and the latter extend inwardly from theperiphery but terminate short of the bore IS. The function of adjustingslots 22 is primarily to increase the flexibility of the gage body andto effect uniform contraction and expansion of the gaging bore [6. Anydesired number of adjusting slots may be provided, depending upon thesize of the gage body and the range of adjustment, and they preferablydecrease in depth away from the locking slot 20, as shown in Fig. 1. V

atoesae Extending axially through the locking slot 20 and seating inlongitudinally tapered grooves 24 and 26 provided in the ends of thebody is a tapered locking pin 28. When pin 23 is driven solidly intolocking slot 20, it expands the gage body It against the adjustingelements [2 and I4 and holds the parts in selected adjusted positions.As best shown in Fig. 2, countersinks 30 and 32 radially relieve theterminal portions of locking pin 28 so that pressure exerted by the pinagainst the walls of slot is confined to the middle portions thereof. Byrelieving the terminal portions of the pin in this manner, there is lespossibility of the gage body being dis torted due to improper fitbetween the pin and the grooves 24 and 26.

The body H! is provided with peripheral threads 1 34 which engageinternal threads 36 of locking elements [2 and it. These threads areadapted to transmit radial thrust from the adjusting element to the bodywhen the iormerare tightened. Any V thread may be used, but it ispreferred to use a 90 thread, as shown in the drawing. In general,threads having a relatively great angle are capable of transmittingpressure from the adjusting elements f2 and M more efficiently thanthreads having a. smaller angle. I

At their inner sides the adjusting elements '2 and M are provided withre-entrant bearing surfaces 38 which are adapted to press against asplit metal ring All which fits in a peripheral groove 42 providedm'edianly in the body Hi. The bearing surfaces '38 preferably aredisposed at an angle of 45, and the groove his formed with a flat bottomwall which is disposed axially of the body. It will be observed that thebearing surfaces 38 first engage ring ill while the adlusting members 12and I l are spaced substantially apart. Movementof the adjustingelements axially against the ring Ill, exerts pressure against thelatter which then transmits "a radial compo'n'ent'of such pressureagainst the body 1'0. At the same time, the angul'arly disposed surfacesof threads '34 and 3B, which sustain axial pressureex'erted by theadjusting elements, transmit.

afradial componentjof such pressure agalnstthe body. The combined'radialcomponents of pressure exerted against the body by threads 34 and 36 andby the split metal ring 4E- Contracts the gage body l0.

s disclosed in our'copending application hereinabovere'ferred to, thebody Hlcan'be contracted by threads 34 and '36, only, but a considerablygreater amount of force must be exerted by adjusting elements l2 and I4than if the split metal. ring '48 is also employed. Thus, the ring 48greatly increases the efiiciency of the means for adjustingthe gage body[0. It is estimated that the radially contracting 'force exerted by ring40 is substantially equal to the radially contracting force exerted byallfof the thread surfaces.

, Groove 42. preferably snugly receives the ring All so that the latterhas very little, if any,'lateral or axial movement therein. Thus, thering limits inward movement of the adjusting elements [2 and and,consequently, longitudinally centers. the body Ill in such, elements.This adjustment is automatic and assures full engagement of the threads38 with the external threads 34. Moreover, by recessing the metal, ring46 in the body ill, it remains associated'with the latter when adjustingelements l2 and 14 are removed and thus is not easily lost. U

Any suitable means for rotating adjusting ele-' 4 ments l2 and [4 on thegage body Ill can be employed. One means here shown, by way ofillustration, comprises annular series of holes 44 and 46 in adjustingelements l2 and i4 respectively. The two series of holes have the samecircle diameter, but one series is provided with a greater number ofholes than the other. Thus, when two of the holes align, the holes atopposite sides thereof are progressively offset. In Fig. l the uppermostholes are shown in alignment. To rotate the adjusting elements ['2 andi4, it is merely necessary to drive a tapered pin 48 into two of theofiset holes, as shown in Fig. 3. If the pin '68 is'insertd in theofiset holes at one side of the aligned holes, the adjusting elements l2and M are tightened on the body in, and, if the pin is inserted in theofiset holes at the other side of the aligned holes, the adjustingelements are loosened.

The inner peripheral corners of adjusting elements l2 and 1'4 are formedwith beveled surfaces 50 which accommodate a slitband 52. The latterconveniently maybe made or a suitable plastic material and. is suitablycolored to dis-'- tinguish the go? from the "no go" gage.

Threads 35 necessarily fit rather-loosely on thread 3'4, and thiscondition may cause the adjusting elements 12 and I4 to move radiallyout of alignment when they are tightened. If such misalignment shouldoccur, recesses 53 formed with axially alignedilat bottom surfaces- 52'maybe "provided in place or the beveled sur faces 50 and fitted with "a'rigidmetal band 55 which bridges the adjusting elements l2 and I' l andfits snugly against surfaces 54 to solidly hold the elements inaidalalignmenton the gage body. or course, the out'ersurface of band 56-can'be similarly colored todist'inguish the go gage from the 'no go" gae.

When adjusting the, gage, the usual procedure is to remove'thelocking-pin ze'and'screw amaster thread gage plug into-the-gaging'bore I6. Adjusting elements l2 and M are then tightened until the gage body i0is 'cont'ra'cted'suihciently so that the master plug can'no 'longer' berotated. Locking pin 28 is then'drivenintothe-lookingslot 20 to, expandthe gage body In sufiicientlyso that the master'plug'can be rotatedwithprecisely the desired amount of resistance from the gaging bore Is. Theplug then removed, andthe gage is properly set to testany workpieceidentical to the plug, It will be readily apparent thatexpansion of thegage bod so increases'the friction between threads 3-4 and. 36. that theadjusting elements. lzfand'ld are. positively locked in theselected,jadiustedposition. Thus, when the parts areadjusted'inthemanner above described, it is unnecessary to provide -zxtrarieous meansfor locking the. adjusting elements. Friction between the gage andtheadjusting ei'ements'is s'u'fiicient to.hold the latter stationary andthe. gage will not "get out or adjustment during normal. handlingjo'r.abuse.

It is to, be understood tha'tjthe of the invent-ion herewith.shownfandfleseribled are to be taken as. preferredexainpl'e's.ofthesame. ah'dlthat various changes 'in size, shape, and-arrangement ofparts. may be resorted to without departing from thespirit ofthe.inventionpor thescope of'the appe'nd'ed claims.

Havin'gthus described theinvention, we. claim:

,7 1. An adjustable ring gage. comprising a r'adially contractible gagebody having, a gaging bore; apair of. adjusting, elements axially 'movable on the body and'having radially extending annular confrontingsurfaces, the confronting surfaces of said elements provided withre-entrant bearing surfaces which face the periphery of the body andco-operate therewith to define a cavity; and a thrust member in saidcavity seating on the periphery of the body and simultaneously engagingthe bearing surfaces, the arrangement being such that pressure imposedon said thrust member by the bearing surfaces is transmitted to the bodywhereby to contract the same.

2. An adjustable ring gage comprising a radially contractible gage bodyhaving a gaging bore; a pairof adjusting elements axially movable on thebody and having radially extending annular confronting surfaces, theconfronting surfaces of said elements provided with axially alignedre-entrant bearing surfaces which open against the peripher of the body;and a split ring member disposed between the body and said adjustingelements engaging the body and said bearing surfaces simultaneously totransmit force from the adjusting elements substantially radiallyagainst the body whereby to contract the latter.

3. An adjustable ring gage comprising a radially contractible gage bodyhaving a gaging bore; a pair of adjusting elements axially movable onthe body and having radially extending annular confronting surfaces, theconfronting surfaces of said elements provided with re-entrant bearingsurfaces which face the periphery of the body and co-operate therewithto define a cavity; means for positively moving said adjusting elementsaxially on the body and for holding the same in a selected adjustedposition; and a radially split, contractible thrust member in saidcavity seating on the periphery of the body and simultaneously engagingthe bearing surfaces, the arrangement being such that pressure imposedon said thrust member by said bearing surfaces is transmittedsubsantially radially against the body whereby to contract the same.

4. An adjustable ring gage comprising a radially contractible gage bodyhaving a gaging bore; a pair of adjusting elements axially movable onthe body and having radially extending annular confronting surfaces, theconfronting surfaces of said elements provided with annular re-entrantbearing surfaces which open against the periphery of the body; means forpositively moving said adjusting elements axiall on the body and forholding the same in a selected adjusted position; and a radially split,contractible ring member disposed between the body and said adjustingelements engaging the body and said bearing surfaces simultaneously totransmit force from the adjusting elements substantially radiallyagainst the body whereby to contract the latter.

5. An adjustable ring gage comprising a radially contractible gage bodyhaving a gaging bore; a pair of adjusting elements axially movable onthe body and having radially extending annular confronting surfaces, theconfronting surfaces of said elements provided with annular reentrantbearing surfaces which open against the periphery of the body; means forpositively moving said adjusting elements axially on the body and forholding the same in a selected adjusted position; means for positivelyholding the adjusting elements axially aligned on the body; and aradially split, contractible ring member disposed between the body andsaid adjusting elements engaging the body and said bearing surfacessimultaneously to transmit force from the adjusting elementssubstantially radially against the body whereby to contract the latter.

6. An adjustable ring gage comprising a radi-' ally contractible gagebody having a gaging bore; a pair of adjusting elements axially movableon the body and having radially extending an-v nular confrontingsurfaces, the confronting surfaces of said elements provided withannular re-entrant bearing surfaces which open against.

bearing surfaces simultaneously to transmit forcefrom the adjustingelements radially against the body whereby to contract the latter.

'7. An adjustable ring gage comprising a ra-- dially contractibleexternally screw-threaded gage body having a gaging bore; a pair of ad-'justing elements independently received on the body, said elementshaving internal screw threads engaged with the external threads of thebody and the confronting surfaces of said elements provided with axiallyaligned re-entrant bearing surfaces which open against the periphery ofthe body, said external and internal threads having surfaces disposed atan angle to the axisv of the gage; and a thrust member seating againstthe periphery of the body and simultaneously engaged by the bearingsurfaces, said thrust member holding the adjustable elements normallyseparated whereby tightening of said elements against the thrust memberapplies radial pressure on the body simultaneously through the threadsurfaces and said thrust member.

8. An adjustable ring gage comprising a radially contractible externallyscrew -threaded gage body having a gaging bore; a pair of adjustingelements independently received on the body, said elements havinginternal screw threads engaged with the external threads of the body andthe confronting surfaces of said elements provided with axially alignedre-entrant bearing surfaces which face against the periphery of thebody; said external and internal threads having surfaces disposed at anangle to the axis of the gage; means for positively holding theadjusting elements in axial alignment on the body; and a radially split,contractible thrust member seating simultaneously against the peripheryof the body and said bearing surfaces, said thrust member holding theadjusting elements normally separated whereby tightening of saidelements against the thrust member applies radial pressure on the bodysimultaneously through the threads surfaces and said thrust member.

9. An adjustable ring gage comprising a radially contractible externallyscrew -threaded gage body having a gaging bore; a pair of adjustingrings surrounding the body and having internal screw threads engagedwith the external threads of the body, said external and internalthreads having surfaces disposed at an angle to the axis of the gage,the confronting surfaces of said adjusting rings provided with annularre-entrant bearing surfaces which open against the periphery of thebody; a radially split, contractible ring member surrounding and snuglyfitting the body and simultaneously engaged by the bearing surfaces; andmeans for positively holding the adjusting rings in axial alignment Iant-he body, said split ring member holding the adjusting :rings;normally separated whereby tightening of the latter rings-against theysplit ring member applies radial pressure TO the body simultaneouslythrough the thread surfaces and said split ring member.

10. An adjustable ring gage. comprising. a radially eontractfoleexternally screw-threaded gage body having a gaging bore; a pair ofadjusting rings independentlyreceived on the. body, said ringshavinginternal serewthteads engaged with'zthe external threads of thebody and said external and internal threads having surfaces disposed atan angle to the. axis of the saga, the confronting surfaces oi saidrings provided with annular rev-entrant bearing surfaces. which openagainst the periphery 'oi the body; alrigid band surrounding and snuglyfitting the adjusting rings for holding the latter axially aligned onthe body, and a split :wirering mounted on the body, said .w-ire.ringhsimultaneously engaged by the periphery -.of the body and saidbearing surfaces and holding'theadiusthig rings normally separatedwhereby tightening of the latter rings thereagainst applies radialpressure on the body simultaneously through the thread surfaces and saidsplit-"ring member.

11. An adjustable ring gage comprising a radially oontractible.externally screw threaded gage body having a gaging. bore and an annularperipheral groove; a pair of. adjusting ring; elements independentlyreceived on the body, said elements having. internal screw threadsengaged with the external threads of the body and said external, andinternal threads having surfaces.

disnosed-atan angle to the axis of the gage, vthe confronting surfacesof said elements provided with annular re-entrant bearing surfacesdisposed at opposite sides of said annulargroove; and a split ringdisposed in the groove and adapted to. be simultaneously engaged by saidbearing surfaces, the arrangement being such that axial movement of thering on the body is limited by the side walls of the groove whereby saidring automatically centers the gage body longitudinally in the adjustingring elements and also assists the thread surfaces in transmittingpressure from the adjusting ring elements radially against the body whensaid rings are tightened-on the body.

GEORGE .HOHWART.

ERNEST F. HOHWART.

REFERENCES CITED The following references are of record in the file oithis patent:

UNITED STATES PAIm 'NTS Number Name Date 1,282,392 Doonaevski Oct. 22,1918 2,000,733- Muller May 7, 1935 2,353,625 .Schnaars July '11, 19 42,356,133, Van den Kieboom Aug. 22, 194A 2,413,566 Hohwart et aL Dec.31, 1.9.46

FOREIGN PATENTS Number Country Date 35356.74 Germany May 23, 1922

